2004-3-22
This is Steve Ember with the VOA Special English Agriculture
Report.
The idea to grow a crop that improves the land and prepares it
for other crops is thousands of years old. But scientists continue
to search for new and better ways to use what are called cover
crops.
Aref Abdul-Baki is with the Agricultural Research Service of the
United States Department of Agriculture. He works at the Sustainable
Agricultural Systems Laboratory in Beltsville, Maryland.
Mister Abdul-Baki has found some cover crops that resist worms
that attack tomatoes. These crops are sunn hemp, cowpea and velvet
bean. They are planted during the months when the main crops are not
normally grown. In states with moderate climates like Maryland and
Virginia, the winter months are a good time to grow cover crops.
For tomatoes, cover crops can be planted in September. They can
be turned over in the soil in May. The same method can be used for
other summer crops like peppers, sweet corn, green beans and some
melons.
After the cover crop is cut and turned, the result is a layer of
organic material. This will provide fertilizer for the new crop.
Also, the cover crop provides extra nitrogen to the soil.
Cover crops mixed with soil into mulch prevents the growth of
unwanted plants. It also keeps soil from drying out and prevents the
loss of soil.
In hot, dry parts of California, cover crops help keep down soil
temperatures. They also reduce water loss and erosion.
Mister Abdul-Baki has shown that cover crops can save farmers a
lot of money. Tomato farmers, for example, have used methyl bromide
to treat their soil before they plant their tomatoes. This chemical
kills many kinds of organisms that harm crops. Such treatment can
increase the size of the harvest. But the government restricts the
use of methyl bromide. And countries have agreed to an international
treaty to ban it.
Mister Abdul-Baki has found that farmers who use cover crops with
tomatoes save one-thousand-four hundred dollars per hectare. Farmers
save on chemicals and also fertilizer. And Mister Abdul-Baki says
the farmer produce as many, or more, tomatoes per hectare as
compared to no use of cover crops.
Some cover crops provide enough seed for the next growing season.
This can reduce costs even more.
This VOA Special English Agriculture Report was written by Mario
Ritter. This is Steve Ember.